Clinical outcome of pretreated B-cell chronic lymphocytic leukemia following alemtuzumab therapy: a retrospective study on various cytogenetic risk categories

Patients with B-cell chronic lymphocytic leukemia (CLL) with 17p deletion respond poorly to chemotherapy. This retrospective study evaluated the benefit of alemtuzumab monotherapy in unselected patients with advanced CLL in the various cytogenetic subgroups. Data were collected from 105 consecutive, pretreated, cytogenetically defined patients who had received alemtuzumab. Response, progression-free survival (PFS), and overall survival (OS) were assessed. The hierarchic incidence of cytogenetic abnormalities was: 13q deletion (as sole abnormality), 18%; trisomy 12, 13%; 11q deletion, 19%; 17p deletion, 33%; and none of these, 16%. Overall response rate (ORR) was 43% in the total cohort and 49% in the subgroup of 17p-deleted patients (n = 35). From the start of alemtuzumab monotherapy, median PFS in the total cohort and in the subgroup of 17p-deleted patients was 7.0 and 7.1 months, respectively. Median OS in the total cohort and in 17p-deleted patients was 32.8 and 19.1 months, respectively. The poor-risk group of patients with CLL (i.e. fludarabine resistant, 17p deletion; n = 20) showed encouraging ORR, PFS, and OS (35%, 7.0 and 19.2 months, respectively). Alemtuzumab was effective in treating patients with CLL across the cytogenetic categories evaluated, but there were differences. In patients with CLL with 17p deletion quite favorable ORR, PFS, and OS were achieved.